Popular

November 12, 2008

Google Plays Part In Flu Season

by Sam Savage

A partnership between Google and the U.S. Centers for Disease Control and Prevention has produced an online tool that may help people know about flu outbreaks even more quickly than existing surveillance methods.

Google Flu Trends uses search terms that people put into the Web-based search engine to figure out where influenza is heating up.

It will then publish a map of affected areas in its new service.

"We've discovered that certain search terms are good indicators of flu activity," Google said in a statement.

"What this does is it takes Google search terms of influenza-like illness and influenza and it emulates a signal that tells us how much influenza activity there was," said Dr. Lyn Finelli, chief of influenza surveillance at the CDC.

Studies show people searching for health information make up 35 to 40 percent of all visits to the Internet.

Influenza kills an estimated 36,000 people a year in the United States and 250,000-500,000 globally.

"As with any communicable disease, early detection is key for health professionals to react quickly," said Jeremy Ginsberg, the lead engineer who developed the new site.

"With online search queries, what we see is millions of people who are interested in searching online for information about health. And with winter approaching, more people will be curious about flu, because we are entering the flu season."

Google is not releasing the search, but influenza-like illnesses include symptoms such as fever, muscle aches and cough. Sneezing usually occurs with other viruses such as rhinoviruses.

The CDC relies currently on centers that report on people coming to their doctors with flu-like symptoms, and lab tests that confirm whether a patient has influenza.

However, many people with flu never visit a doctor, and the CDC's surveillance data is about two weeks behind.

The Google tool will track flu activity in near real time, the company said.

"One thing we found last year when we validated this model is it tended to predict surveillance data," Finelli said.

"The data are really, really timely. They were able to tell us on a day-to-day basis the relative direction of flu activity for a given area. They were about a week ahead of us. They could be used ... as early warning signal for flu activity."

Google is not charging for the service. "They are giving it to the world for free," Finelli said.

A paper accompanying the launch of the site was accepted by the journal Nature, with the editor in chief, Philip Campbell, praising the "exceptional public health implications of this paper."

The journal is allowing the paper to be discussed with the public before it is published.